Frank rhind



(No Model.)

F. RHIND.

CENTRAL DRAFT LAMP.

No. 364,438.. Patented June 7, 1887.

N. PETERS. Photo-WW. WM. D. C-

UNITED STATES PATENT OFFICE.

FRANK RHIND, OF MERIDEN, CONNECTICUT, ASSIGNOR TO EDWARD MILLER & COMPANY, OF SAME PLACE.

CENTRAL-DRAFT LAMP.

SPECIFICATION forming part of Letters Patent No. 364,438, dated June '7, 1887.

Application fi'ed January 524, 1887, Serial No. 225,264. (No model.)

' in Central-Draft Lamps; and I do hereby declare the following, when taken in connection with accompanying drawings, and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in-

Figure 1 a vertical central section of the central draft-tube, auxiliary tube, and its extension, with so much of the burner and fount as are necessary to the understanding of the invention; Fig. 2, an upper end view of the central draft-tube; and Fig. 3, a side view of the upper end portion of the central drafttube, illustrating the method of forming passages between the auxiliary tube and the drafttube for the return of oil to the fount.

This invention relates to an improvement in that class of lamps in which the wick is of tubular form, with an air tube or passage within the Wick, and through which air flows to aid in the support of combustion, and commonly called central-draft lamps, this being an improvement on what is known in the market as the Rochester lamp. In thislamp,andlamps 0 of this class, the innertube is provided with an extension above the top of the wick, which extension is closed at the top, but its sides perforated to form a distributer for the air which passes up through the central tube, and to cause it to flow evenly to and upon the inside of the flame. As heretofore constructed this extension of the inner tube or central draftpassage has been in the from of a cup or thimble, the sides of which are perforated, the

thimble introduced into the inner tube the closed end up, the thimble being somewhat less in diameter than the drafttube, but constructed with a flange at its lower edge which will closely fit the inner surface of the draft- 4 5 tube, and so that it may be supported in the inner tube. This thimble is necessarily removable, both for convenience of manufacture and for convenience of trimming the wick.

In replacing thethimble, as after trimming,

unless care be exercised to bring it into a truly concentric or axial position-that is, if it stand inclined to the axis of the draft-tube-the perforations on one side will be brought nearer the flame than upon the opposite side. The result of such niisplacement of the thimble is 5 5 such an imperfect supply of air to the flame as to cause it to burn irregularly or imperfectly, and frequently to smoke. Again, the upper end of the wick or base of the flame is necessarily above the top of the inner tube, and the Go draft of oil is frequently in excess of consumption, or, when not burning, if the wick stand with its end above the inner tube, absorption will draw the oil through the wick to the top, and it naturally escapes over the inner end of the draft-tube, and as this draft-tube isnecessarily open at the bottom for the admission of air it follows that oil passing into this drafttube will flow down and upon the table or rest below. 7

The object of my invention is to overcome these difficulties; and it consists, principally, in constructing the thimble as an auxiliary tube, adapted to pass down upon the outside of the draft-tube, and so as to surround the tube' with sufficient bearing to insure its concentric or axial position when in place, and whereby the oil drawn up by the wick, as be fore described, will pass through the said auxiliary tube, and then down between it and out Sc side the inner tube, and thence return to the fount.

A represents the fount, B the inner or coir tral draft-tube, and which is of an extcrnaldiameter corresponding substantially to the in- 8 5 ternal diameter of the wick,and so as to form the inner wielctube. I show only a portion of the burner, as that is unnecessary to theunderstanding of my invention; nor do I show the wickhdjuster, which is also unnecessary to the invention.

D represents the tube, which is formed as a part of the burner and which extends down outside the wick, and so that the wickchanr her is a concentric space between the draft- 5 tube B and the outer tube, D.

In the best construction of my invention the upper end of the tube Bis turned inward, or contracted, as at a.

1) represents the auxiliary tube, the internal 10o diameter of which corresponds to the external diameter of the draft-tube B, and so as to slide down over the upper end of the tube with substantially frictional contact. The auxiliary tube is closed at its upper end, and the sides of the extension of the auxiliary tube above the upper end of the wick-tube are perforated, as shown, to form a concentric air-distributer, so that air which passes up through the draft-tube Bwill escape through the air-distributer radially against the inside of the flame. This auxiliary tube is made of thin metal, so as to readily set between the wick and the draft tube without hinderance to the proper adjustment or movement of the wick.

The upper end of the auxiliary tube is best made of less diameter than the central tube,B. It is therefore contracted through that portion which is to be perforated, and so as to form a shoulder, at, which may rest upon the upper end, a, of the inner tube, 13, as seen in Fig. 1. The shoulder of the auxiliary tube is perforated, the perforations opening onto the inwardly turned or contracted end of the inner tube, and so that oil escaping from the wick may pass through the perforations in the shoulder onto the outer surface of the draft-tube; and as it comes upon the draft-tube below its upper end the oil necessarily flows down between the auxiliary tube and the drafttube and returns to the fount from whence it came.

While the oil will pass between the two tubes even with so close a fit between the two tubes that the tube will be supported by frictional contact, to insure the proper escape of the oil the draft-tube should be constructed with one or more vertical channels, 6, (see Figs. 2 and 3,) these channels being madeby making vertical indentations or corrugations in the surface of the tube around its upper end, the grooves extending down to a point below the auxiliary tube, and so that they form free passages for the oil between the two tubes.

I prefer to make the perforated extensions or air-distributer portion of the auxiliary tube of less diameter than the draft-tube, both for the purpose of forming a secure hearing or rest for the auxiliary tube, as well as a better distribution of air to the flame than would be accomplished by making the perforated portion ofequal diameter with the auxiliary tube; but the perforated extension may be of equal diameter, as indicated by broken lines, Fig. 1. I11 that case there should be a rest formed on the inner tube-say as at f, broken lines, Fig. 1-and upon which the auxiliary tube may stand, so that its proper elevation will be insured.

By the construction which I have described the proper location of the auxiliary tube is insured, for the reason that it cannot be wronglyinserted, nor can it be applied other than in a truly concentric or axial position,

Again, by making a passage or passages downward between the inner or central draft-tube and the auxiliary tube the overflowing oil is surely reconveyed to the lamp-fount, and thus the difficulties which I have mentioned as existingin the Rochester and similar lamps are avoided.

I do not wish to be understood as claiming, broadly, providing the cental draft-tube with a surrounding concentric tube within the wick to form a return-passage for the oil, as this, I am aware, is very old.

I do not wish to be understood as claiming, broadly, an auxiliary or air-distributing tube having its upper end reduced in diameter so as to form an annular shoulder on said auxiliary tube, as such is a common and well-known construction, the essential feature of my invention being the construction of the auxiliary or air distributing tube so as to set over the end of the inner wiek-tube and extend down into the wick-chamber, in order that thejoint between the inner wick-tube and the auxiliary tube may open into the wick-chamber instead of into the air-tube, as in previous construe tions; but

\Vhat I do claim, and desire to secure by Letters Patent, is-

1. In a tubular-wick or central-draft lamp, the combination of a central draft-tube forming the inner wick-tube, open for the admis sion of air, an auxiliary tube the internal diameter of which corresponds to the external diameter of said inner tube, and adapted to set over the upper end of said inner tube, the said auxiliary tube constructed with an ex tension above the inner tube of a diameter less than the diameter of the said inner tube, and so as to form an annular shoulder as a rest upon the upper end of the inner tube, the sides of said extension perforated to form an air-distributor, substantially as described.

2. In a tubular-wick or. central-draft lamp, the combination of a central draft-tube forming the inner wick-tube, an auxiliary tube adapted to set over the upper end of the said inner tube and constructed with an extension above the end of said inner tube, the auxiliary tube closed at its upper end, the sides of the extension perforated to form an air-distributer, and the said tubes constructed with one or more passages between them leading downward to the oil-reservoir, substantially as described.

FRANK RHIN D.

\Vitnesses:

GEo. L. Coornn, T. J. RonY. 

